Non-lethal, low-energy marking projectiles are often used in connection with small-caliber rifled weapons (e.g., pistols, rifles, submachine guns, and the like) to provide a realistic training experience. Such projectiles typically include a polymeric frontmost shell portion enclosing a semi-viscous color marking compound and a rear base portion that engages the shell portion. Engagement between the shell and base is typically provided via an interference fit or snap-fit. The shell portion is configured such that, during impact, the marking compound is expelled from the shell in a controlled manner, typically along pre-defined break lines.
Known polymer marking projectiles may be unsatisfactory in a number of respects. For example, sub-optimal storage of such projectiles—particularly projectiles utilizing water-based marking compounds—can result in significant moisture evaporation through the shell/base interface and consequently a reduction in viscosity and mass of the marking compound. This aging effect, which is exacerbated by high temperature and humidity conditions, is due in part to the difficulty in achieving an airtight seal between polymeric components, which are notoriously subject to high dimensional tolerances and various assembly constraints.
Premature aging in the form of moisture loss and marking compound phase change may result in a diminished marking effect and/or a non-uniform mass distribution, which itself can lead to a reduction in gyroscopic stability at the weapon muzzle. Furthermore, within any particular batch of marking projectiles, the moisture-loss may vary widely between individual projectiles. This results in an increased variation in projectile muzzle velocity and increased impact dispersion.
Accordingly, it is desirable to provide improved polymer marking projectiles with improved shelf life and flight stability. Other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.